Arsenic removal performance of granular adsorbents using novel clinoptilolites modified with iron nanoparticles

Abstract

In this research, novel beads were successfully synthesized from natural clinoptilolite (CL) modified with iron nanoparticles (FCL). Beads were prepared using alginate (A) and chitosan (C). FESEM, EDX, XRD, and FTIR techniques were employed to characterize the CL, FCL, A-bead, and C-bead. A comprehensive series of batch adsorption experiments were conducted utilizing both prepared samples to study the influential parameters. The most effective cross-linking solutions of chitosan and alginate were sodium tripolyphosphate/sodium hydroxide and 4% Ferric chloride, respectively. The optimum ratio of chitosan/FCL and alginate/FCL was 1:3 and 1:4, sequentially. The effect of initial arsenic concentration, and adsorbent concentration were evaluated. The optimal removal rate of 86% and 93.27% were found for A-beads and C-beads using their optimized initial concentration. Moreover, the best arsenic removal performance was seen 1 g/L for both A-beads and C-beads. The removal rate of 0.3, 0.6, 1, 1.5, and 2 g/L of alginate was 75.12%, 81.15%, 82.21%, 82.90%, and 83.15%, respectively. On the other hand, C-beads had higher removal rates at the considered contents. The removal rate of 0.3, 0.6, 1, 1.5, and 2 g/L of C-beads were 75.18%, 88.78%, 91.86%, 92.25%, and 92.4%, respectively. Additionally, Langmuir and Freundlich isotherms were employed to find the maximum adsorption capacity. The maximum adsorption capacity of qmax of alginate and chitosan beads was 10000 𝜇g/g.